技術標籤：java

轉載於：https://blog.csdn.net/Dimpies/article/details/104024002

import java.util.ArrayList;

public class AffineDecode {

	public static void main(String[] args) {
		String Qr_Str="3A56B45C5D52EF45451G";
		System.out.println("待處理的字串："+Qr_Str);
		String Affine=Affine_Str(Qr_Str);//提取明文資訊
 

		int[] key=key(Qr_Str);//提取金鑰
		Affine_Code(Affine,key);//提取紅外碼
	}
	
	public static String Affine_Str(String Qr_Str) {
		char[] chars=Qr_Str.toCharArray();
		char[] Str_a=new char[7];
		int str_index=0;
		ArrayList<Integer> array=new ArrayList<Integer>();//定義動態陣列

		for(int i=0;i<Qr_Str.length
 
();i++) {
			if((chars[i]>='A'&&chars[i]<='Z')) {
				Str_a[str_index]=chars[i];
				str_index++;
				if(str_index==8) {
					break;
				}
			}
		}
		
		String Affine_a=new String(Str_a);
		System.out.print("提取的明文資訊："+Affine_a);
		System.out.println();

		return Affine_a;
	}
	
	public
 
 static int[] key(String Qr_Str) {
		char[] chars=Qr_Str.toCharArray();
		ArrayList<Integer> array=new ArrayList<Integer>();
		int[] key=new int[2];

		for(int i=0;i<Qr_Str.length();i++) {
			if((chars[i]>='0'&&chars[i]<='9')) {
				int num=(chars[i]-'0');
				array.add(num);
			}
		}
	
		System.out.print("提取出來的數字:");
		for(int n:array) {
			System.out.print(n);
		}
		
		key[0]=array.get(0);
		key[1]=array.get(array.size()-1);
		System.out.println();
		System.out.format("金鑰: K=(%d,%d)",key[0],key[1]);
		
		return key;
	}
	

	
	public static int[] Affine_Code(String Affine,int[] key) {
		int[] infrared_coder=new int[6];
		int k3=((26+1)/key[0]);//(K3*K1)%26=1;K1=3,求最小模逆K3=(1+26(n))/3(K1)
		int k2=key[1];
		
		char[] Affine_AZ=Affine.toCharArray();
		char[] Affine_az=new char[7];
//		Affine_az[0]=(char) ((k3*((Affine_AZ[i]-'A')-k2)%26)+'a');
		for(int i=0;i<7;i++) {
			if((Affine_AZ[i]-'A')<k2) {
				Affine_az[i]=(char)((k3*((Affine_AZ[i]-'A')-k2)%26+26)+'a');
			}else {
				Affine_az[i]=(char)((k3*((Affine_AZ[i]-'A')-k2)%26)+'a');
			}
			
		}
		
		for(int i=0;i<6;i++) {
			if(i%2==0) {
				infrared_coder[i]=Math.abs(Affine_az[i+1]-Affine_az[i]);
			}
			else {
				infrared_coder[i]=Math.abs(Affine_az[i+1]+Affine_az[i]);
			}
	
		}
		System.out.println();
//		System.out.println(Affine_az[0]);
		
		for(char n:Affine_az) {
			System.out.print(n);
		}
		System.out.println();
		System.out.print("紅外碼：");
		for(int n:infrared_coder) {
			System.out.print(Integer.toHexString(n)+" ");
		}
		
		return infrared_coder;//返回紅外碼
	}
}